\section{Method}
\subsection{Selecting pictures from the database}
The FRGC dataset consist more then…. pictures of more then …. different persons. Since it is not possible to analysis all pictures from the database.  A selection of the dataset will be analyzed.  

Since it is interesting to know why some individuals have better recognizing performance then others there should be no different in the circumstance the picture is taken. Therefore, only pictures taken in a controlled light environment are taken form the dataset. 

To get a reliable estimating of the true-match rate there should be enough pictures per individual. A minimum of 20 pictures per individual is chosen. 

Test was performed with 31 individuals. From every individual are exact 20 pictures in the dataset. So in total are there 620 different pictures which will be analyzed.  

\subsection{Get the score matrix from Verilook}
Verilook is face recognition software. Verilook can compare two pictures from individuals and give matching score of these two pictures. These scores will be higher when there is a better match. 

All scores are saved in a score matrix. Because every picture is compared to every other picture in the selected dataset. This matrix has 620 columns and 620 rows. 

Comparing picture 1 to picture 2 gives the same result as comparing picture 2 to picture 1. Therefor only half of the matrix is filled in by Verilook. 

Furthermore, comparing a picture to exact the same picture will always give the maximum score.  Therefor this scores are not calculated by Verilook. 

When Verilook cannot calculate a matching score, a score of minus 1 is saved in the matrix. A real matching score is always positive. This way the minus 1 scores can easily be filter out in further analysis. 

Verilook is not a stable program, after a random amount of comparisons the Ncore.dll crashed. To work around this problem a watch dog program was written. This program gets the status of the Verilook process and when the process is not responding it will restart the process. After every comparison the calculated score together with the status variables is saved. When the process restart, it continues where it left off. 

\subsection{Get the ROC from every subject}